1 files changed, 59 insertions, 0 deletions
diff --git a/arch/m68k/include/asm/segment.h b/arch/m68k/include/asm/segment.h
new file mode 100644
index 000000000..2b5e68a71
--- /dev/null
+++ b/arch/m68k/include/asm/segment.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _M68K_SEGMENT_H
+#define _M68K_SEGMENT_H
+
+/* define constants */
+/* Address spaces (FC0-FC2) */
+#define USER_DATA     (1)
+#ifndef __USER_DS
+#define __USER_DS     (USER_DATA)
+#endif
+#define USER_PROGRAM  (2)
+#define SUPER_DATA    (5)
+#ifndef __KERNEL_DS
+#define __KERNEL_DS   (SUPER_DATA)
+#endif
+#define SUPER_PROGRAM (6)
+#define CPU_SPACE     (7)
+
+#ifndef __ASSEMBLY__
+
+typedef struct {
+	unsigned long seg;
+} mm_segment_t;
+
+#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })
+
+#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
+/*
+ * Get/set the SFC/DFC registers for MOVES instructions
+ */
+#define USER_DS		MAKE_MM_SEG(__USER_DS)
+#define KERNEL_DS	MAKE_MM_SEG(__KERNEL_DS)
+
+static inline mm_segment_t get_fs(void)
+{
+	mm_segment_t _v;
+	__asm__ ("movec %/dfc,%0":"=r" (_v.seg):);
+	return _v;
+}
+
+static inline void set_fs(mm_segment_t val)
+{
+	__asm__ __volatile__ ("movec %0,%/sfc\n\t"
+			      "movec %0,%/dfc\n\t"
+			      : /* no outputs */ : "r" (val.seg) : "memory");
+}
+
+#else
+#define USER_DS		MAKE_MM_SEG(TASK_SIZE)
+#define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
+#define get_fs()	(current_thread_info()->addr_limit)
+#define set_fs(x)	(current_thread_info()->addr_limit = (x))
+#endif
+
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _M68K_SEGMENT_H */